Our Team


Meet the experts behind our practice


Peter Ziegler, MD

Supervising Physician

Dr. Ziegler is a board-certified family physician with over 25 years of experience in primary care. He earned his Doctor of Medicine at Tufts University and completed his residency in family medicine at Brown University. He worked for 18 years with the Indian Health Service, then at Assurance Health and Wellness, and most recently at Community Partners, Inc. integrating primary care with behavioral health services. Dr. Ziegler believes in the importance of connection and communication with his patients to best assist with their healthcare needs. 

Juniper Dery-Chaffin, PA-C

Physician Assistant

Juniper earned her Master of Physician Assistant Studies from Northern Arizona University and Master of Educational Psychology from the University of Arizona. She works as a family medicine physician assistant providing primary care services, including, but not limited to, general family medicine, outpatient procedures, annual wellness exams, preventative medicine, chronic disease management, pain management, and well-woman exams. In addition to outpatient care, Juniper is responsible for primary care rounding through Escalera Health at Cornerstone Behavioral Health El Dorado in Tucson. She treats primary care and behavioral health patients at Escalera. 


Sarah Herndon, LMSW

Licensed Therapist | Therapy Supervisor

Sarah attended the University of Arizona for her Bachelor’s Degree in Sociology and Hawaii Pacific University for her Master’s Degree in Social Work. Sarah is a Licensed Master Social Worker passionate about empowering her clients to make successful, lasting progress toward their goals. Her professional background includes work in international and domestic adoption, youth LGBT+ advocacy, chronic and terminal illness counseling, general mental health and serious mental illness therapy, medical management, and human trafficking survivor advocacy. Sarah has served as a Field Instructor for MSW students and is active in the Tucson community’s human and animal rights sector. Sarah’s therapeutic approach includes cognitive behavioral therapy, mindfulness, positive psychology, and motivational interviewing. Prior to joining the Escalera Health team, Sarah worked in facility administration, quality improvement, and regional-level management for medical clinics.

Angela Daniels-Valenzuela, LISAC

Licensed Therapist

Angela received two Masters Degrees, the first in Art Therapy and Counseling and the second in Human Resources and Substance Abuse Counseling. She has over 21 years of experience working with adults, children, and families with numerous behavioral health issues. In addition to traditional talk therapy, Angela utilizes Art Therapy as a supplemental tool to aid expression of especially difficult issues. This therapeutic technique allows exploration of various issues through art-making and can be healing. Angela has experience working with blended families, partners in interracial relationships, individuals struggling with bi-racial identity or multi-ethnicity, and individuals involved in probation and Child Protective Services. Angela’s patients represent a variety of cultures, including members of tribal communities in Arizona.

Jo-Ann Marcus, LCSW

Licensed Therapist

Jo-Ann is a graduate of the University of Chicago and the University of New England. Her therapy style is collaborative, pragmatic, and compassionate. She has extensive experience helping clients who are struggling with loss and grief, life transitions, divorce, stepfamilies and parenting, domestic violence, workplace issues, and depression. Jo-Ann helps people find better ways of dealing with stress and anxiety, as well as internal conflict and strained relationships. 


Dara Dupree, LCSW

Licensed Therapist​

Dara earned her Bachelor’s and Master’s in Social Work at Arizona State University. She provides compassionate whole health approaches including Mindfulness, CBT-Trauma Informed, Couples Counseling, Motivational Interviewing, Substance and Relapse Prevention, Grief and Loss, and psychoeducational tools to improve coping skills and communication techniques. Dara has worked with adolescents and adults in community behavioral health and hospital settings for over 25 years. 

Andrea Moreno, LMSW

Licensed Therapist​

Andrea received her Masters in Social Work from Arizona State University and earned certifications in Solution Focused Brief Therapy, ASU Latino Cultural Competency in Social Work, Crisis Prevention Intervention, Suicide Prevention and Awareness, Trauma Informed Care and Cognitive Behavioral Therapy. She has worked with both children and adults providing behavioral health assessments, individual and group counseling intervention services, therapeutic plans, safety plans, and reunification planning. Through psychoeducation and empathic listening, Andrea helps her clients reach their recovery goals. She is fully bilingual and emphasizes patience and respect to successfully work with individuals from a variety of cultural backgrounds.

Arlene Woolfolk, LAC

Licensed Therapist

Arlene’s experience is in individual counseling, family counseling, treatment planning, individualized assessments, and trauma informed crisis management. A University of Arizona graduate with a master’s in mental health counseling, Arlene uses psychoeducation to promote client understanding regarding the impacts of trauma as it relates to integrated care services. This covers treatment issues (including medication), official diagnoses, and relevant skills training. She approaches therapy with professionalism, warmth, empathy, acceptance, and humor. 

Amber Gin, LMSW

Licensed Therapist​

Amber provides person-centered therapy with compassion and empathy through an integrated approach. She earned a Bachelor’s Degree in Psychology from the University of Arizona and a Master’s Degree in Social Work from Arizona State University. Amber works with adults of all ages who are dealing with anxiety, depression, life transitions, grief and loss, and low self-esteem. She specializes in therapy with older adults and has extensive experience with informal caregivers and families of loved ones living with Alzheimer’s disease and related dementias.



Jamie Walker, RN


Lesette Amos